Wikipedia:Reference desk/Archives/Computing/2009 March 23

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March 23[edit]

Windows EXE's on Mac OS x x86[edit]

How can I run .exe's on Mac OS X x86. I downloaded the Mono Project for a .NET framework for Mac OS X. Is it all I need? And what about WINE, it says on some pages on its site that it can be used for Mac OS X, but on the downloads page I can't find the one for Mac OS X. I'd really like some help with this. I'm looking for a free way to do this. --Melab±1 01:31, 23 March 2009 (UTC)

The Mono tools will only let you run .exe's that were built with .NET. But for those .exe's, it should work pretty well. According to here: [1] you just have to type "mono myprogram.exe" and if it's a .NET program, it'll run it. I'm not sure how you can find out whether an .exe is .NET compatible or not.
Installing Wine on OS X - [2]. Wine can have trouble with newer software, but if you're really dedicated you can probably get whatever you want to run. Indeterminate (talk) 05:04, 23 March 2009 (UTC)
Bump for Wine. Your milage may vary but I've had success several times with this software. aszymanik speak! 06:19, 24 March 2009 (UTC)
See also Darwine. -- (talk) 08:42, 23 March 2009 (UTC)

Anyone else have one of these stupid things?[edit]

I got an InCharge for PS3, made by TeknoCreations. Here's a pic. The stupid thing didn't work (I'd place a controller in it, the controller lights would blink once, then stay unlit). I managed to take it back and get a new one several months later. The new one still doesn't work, and the behaviour is similar. Anyone had any success getting this thing working, or should I take this one back and stick to USB cables? --Silvaran (talk) 02:36, 23 March 2009 (UTC)

I have to say that inductively charging lithium batteries in a form-factor that fits inside a standard battery bay sounds like a really 'iffy' idea. I'm not surprised they don't work well. But it's surprising that they'd stay in business if they didn't. SteveBaker (talk) 05:45, 23 March 2009 (UTC)
The induction pack clamps onto the back of the controller. It's hard to see in the pic, but it plugs into the USB port on top of the controller and there's a clamp on the bottom of the controller to keep it attached. The pack fits into the base where it's supposed to charge. -- (talk) 13:58, 23 March 2009 (UTC)
I've got a pair of induction charged headsets, and it's a bit touchy about where I place the base unit. I *wanted* to place it right on top of my projector, but it kept turning itself off. (Probably an important safety feature.) I've found that I really can't place it near any other electronic device. It's now sitting on top of a cardboard box on top of my projector until I find a small table for it.
I wonder if you're having a similar issue with your PS3 controllers? APL (talk) 16:02, 23 March 2009 (UTC)
Maybe... though encasing the whole thing in a faraday cage kind of defeats the convenience of having charge by induction :).-- (talk) 18:15, 24 March 2009 (UTC)

recovering CD data[edit]

So I've got some CDs that were probably not "finished" properly, and I'm attempting to recover any data that might be whole on the CD-Rs. I've come across a program called PhotoRec which claims it can recover data from unfinished CD-Rs, but I'm not having much luck figuring out how it works, or it's just not responsive (it just opens a console and says "Please wait..."), so I'm wondering if there is anything else (free) that I could try. Thanks! (talk) 08:22, 23 March 2009 (UTC)

Search for a program called "ISOBuster" - it will probably do it (it will bypass the Window's "please wait" console and go directly to the actual data that is on the CD). There is a free version with some restrictions on its functionality. The program's instructions are very complicated though, and recovering data from a CD that is damaged or only partially readable may take, quite literally, days. Meowy 15:56, 24 March 2009 (UTC)

Hidden files aren't shown[edit]

Recently I can't unhide my jpg files in the folder. I click "show the hidden files and folders", then ok or apply, but nothing changes. The folder shows that the files are there though. (talk) 10:06, 23 March 2009 (UTC)

"Show hidden files" merely shows the files, It won't "unhide" them. To do that you need to either go into the properties of the file and untick hidden or go into the properties of the folder they're in to force everything to unhide in one go. Hope this helps! ZX81 talk 15:05, 23 March 2009 (UTC)
This question isn't clear enough to give a helpful answer. What Operating system are you using? What application are you using to show files and folders. Where are you finding "show the hidden" upon which to click? You say "nothing changes" - What would expect to happen?. How does the folder show they are there? You may mean Windows Xp with Windows explorer and "Tools | Folder options | View". If windows explorer says the file is there, then it is there, otherwise it isn't. Please clarify what you are eeing. -- SGBailey (talk) 15:06, 23 March 2009 (UTC)
I agree it's a little bit unclear, but I can guess from the question that the user is using XP/Vista from the "show hidden files and folders" dialog, and from the fact that xe can see the image files from the preview of the folder contents (i.e. the folder icon includes a little preview of the images in XP/Vista). By "unhide", xe probably means "make visible", i.e. the user knows the files should be there from the previews, but explorer doesn't show any files within the folder. I don't have any answer mind you, other than that the preview might not have been refreshed properly. (talk) 15:33, 23 March 2009 (UTC)
Yep, make visible, I'm using Win XP. I don't know whether it's a temporary issue or something actually has happened. Additionally, it takes too long for my antivirus to download at start now, may be the things are connected. Recent scanning revealed no viruses. (talk) 20:00, 23 March 2009 (UTC)

Copy a binary file in C/C++[edit]

I'm trying to copy a binary file containing random binary characters using a C program to another file. In the process, I want to append some extra data to the file at the beginning and end. Can someone point me in the right direction here, please?-- (talk) 13:39, 23 March 2009 (UTC)

fopen the input file (with mode "rb") and output file (with mode "wb"), fread big blocks of data from the input and fwrite same to output, and keep freading and fwriting until fread returns 0 (or either function returns an error). Then fwrite the stuff you want to append, and then fclose both files. Dog Day Today (talk) 13:51, 23 March 2009 (UTC)

I end up with just a small part of the original file. Somehow the whole of abc.exe (around 3.25 mb) doesnt get copied. After running this, test.exe is only around 360 bytes. Can you please see if I'm doing something wrong?

FILE *ptr1,*ptr2;;
char c[500];
ptr1=fopen("c:\\abc.exe", "rb");
ptr2=fopen("c:\\test.exe", "wb");
while(fread(c, 500, 1, ptr1)!=0)

-- (talk) 14:31, 23 March 2009 (UTC)

I don't immediately see what's wrong with your code, other than you're assuming the read will always get 500 bytes (and you don't check errors). Anyway, this works:
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>

#define BLOCKSIZE 500

int main() {
  FILE*  inFile,
      *  outFile;
  char   data[BLOCKSIZE];
  size_t readsize;

  inFile=fopen("in", "rb");
    perror("opening input file");

  outFile=fopen("out", "wb");
    perror("opening output file");
  do {
    readsize=fread(data,1,BLOCKSIZE, inFile);

    if(readsize) {
      fwrite(data,1,readsize, outFile);
      if(ferror(outFile)){   // need this for stuff like media removed or space exhausted


  return 0;
Dog Day Today (talk) 16:32, 23 March 2009 (UTC)
Actually, on thinking about it, the above code is wrong - I should be checking ferror after every fread too, as an error (say media-removed, network-down) will cause the thing to emit a truncated out file - instead it should close the output file, unlink it, and then die with an error. Dog Day Today (talk) 16:56, 23 March 2009 (UTC)
... which means the fread section look like:
Dog Day Today (talk) 17:52, 23 March 2009 (UTC)
You also need to check the return value of fclose(outFile) because it flushes leftover data from the stdio buffer, and that write may fail. -- BenRG (talk) 23:30, 23 March 2009 (UTC)
Yes, good catch. I wonder how, in practice, one could test that? For testing the failed writes above I simply wrote a large file to a smaller volume, and for testing the failed reads I read from a usb stick and yanked it mid way through. Getting just that fclose to fail is a challenge (bar a dynamic-linking shim, which is cheating). Dog Day Today (talk) 13:56, 24 March 2009 (UTC)

Keep in mind that unlink() is POSIX, not ISO C. Thus it might not be supported by all operating systems. From the original poster's posts, I assume he/she is using Windows. I don't know whether Windows supports unlink(). It would be safer to use remove(), which is ISO C. Also, if you want to be picky about it, the only ISO standard exit() values are 0, EXIT_SUCCESS and EXIT_FAILURE. 0 is guaranteed to mean success but need not actually be the same as EXIT_SUCCESS. JIP | Talk 20:47, 25 March 2009 (UTC)

Making a PDF of a Book[edit]

There are a certain number of books I have, of which I would like to scan and make a .pdf of, basically because they are very old books and some are very valuable to me (personally, not monetarily). Now, what I want to do is make a .pdf of these books by scanning, but with each page kept within one file (i.e. as an acrobat file that I can peruse each page without opening another .jpeg). How do I do this? All I can guess about this is that I may need to scan each individual page then try to sew them together as a .pdf. Is there a free software that eliminated the 'sewing' bit?--KageTora (talk) 15:18, 23 March 2009 (UTC)

Basically, "is there a free alternative to Acrobat"? I don't think so. If there is, I'd like to know... yandman 17:12, 23 March 2009 (UTC)
There are a number of free programs that can do a bunch of things Acrobat can do (although some do some things, some others, and some things aren't done well by anyone, so there isn't a full replacement for Acrobat). Inkscape will open and edit PDFs (which Acrobat really won't). Ghostscript and ImageMagick will convert things into PDF (and sometimes vice versa). PDFtk will do other stuff like merge and split. Dog Day Today (talk) 17:34, 23 March 2009 (UTC)
Use ImageMagick's convert program: convert mouse.jpg cat.jpg dog.jpg output.pdf takes three jpgs and makes a pdf. Dog Day Today (talk) 17:34, 23 March 2009 (UTC)
Some scanning software - eg Canon can do this built in, but it has limited editing, so you would have to get the scan correct first up - ie not skipped pages. Graeme Bartlett (talk) 20:39, 23 March 2009 (UTC)
I think the others have basically covered you, but if you'd like to try something a little different, you could: scan each page and save it as a jpg, zip all those jpgs into a standard zip file with a name like, then rename that file to goodbook.cbz'. That file can be opened with various types of freeware, like Cdisplay. That scenario is typically used for comic books, but works just fine with any kind of jpg. Matt Deres (talk) 19:55, 25 March 2009 (UTC)
I really like "PDFCreator" - it adds a printer to your computer and anything you print to that "printer" will be saved as a PDF. Very handy for quick and dirty PDF creation. ---J.S (T/C/WRE) 16:11, 28 March 2009 (UTC)

Why are console games more expensive?[edit]

The specs are identical. The hardware is (almost) completely identical and the functionality is certainly the same. You've got NONE of the configuration issues that you have with PCs. It must SURELY be simpler to develop for a fixed/known hardware platform like a console than the chip/motherboard/graphics card/memory/Windows zoo that is your "average" PC. And yet console games are about double the price of PC games. Why? (enter SteveBaker, stage left...) Zunaid 15:54, 23 March 2009 (UTC)

I'm no SteveBaker, but I would guess licensing fees, development costs and price agreements. Anyone can release their own computer software, but an "official" PS3 game requires approval from Sony, including expensive development kits, a per-disc licensing fee and possibly even requiring a minimum price. Here's a discussion on the topic. Also, at least a few sources think console game prices might decrease in the near future. – 74  16:23, 23 March 2009 (UTC)
And another answer is simply, "because people will pay those prices". --jpgordon∇∆∇∆ 16:40, 23 March 2009 (UTC)
No - that's absolutely not the reason. ("Trust me - I'm a game developer") SteveBaker (talk) 00:10, 24 March 2009 (UTC)
That is, in fact, the only and complete answer. There is virtually no unit production cost (you burn a CD/DVD, print a label, put it all in a case and transport it, that's all - for the numbers they are producing that probably comes to a few cents per unit), so they determine the price simply by working out the demand/price curve (they have lots of data from previous games, so they should be able to do that pretty well) and pick the price that maximises revenue. The cost of development only determines whether it is profitable to make a game or not, it doesn't determine the price. (I'm grouping the whole games industry into a single entity here, which isn't entirely realistic - there may be per unit licensing costs for the games producer to the console producer, but that's all just money moving within the industry so doesn't make much difference to those of us on the outside.) --Tango (talk) 19:30, 23 March 2009 (UTC)
That's not true though - we have to pay Microsoft or Sony or Nintendo for every copy we sell. Then there is the profit margin for the store that sells it to you. Those are both per-unit costs - and they probably add up to more than half of the shelf price. But the other thing you're missing is that making the game is outrageously expensive. Consider the last game I worked on - we had something like 60 artists, a dozen level designers, a dozen programmers, story writers, motion-capture performers, voice artists, a handful of musicians and audio guys, translators, managers, human resources...about 100 US workers in all, then add another 100 to 200 people 'outsourced' in places like Mexico, India, Singapore churning out 3D models by the bucket load. Our game took three years to build - and for much of that time, it cost a million dollars a month to develop - perhaps $36 million. We had to sell about 5 million units just to break even (that's actually a LOT - sure the GTA VI's and the Halo III's sell in the hundreds of millions - but most games count themselves lucky to hit 2 or 3 million. We also have to pay millions to advertise the damned thing. Then - it's a fact of life - but only about one game in three ever makes it to the store shelves and only about one in thirty actually turns a profit at these supposedly "inflated" prices. I agree 100% that the cost of making the DVD is about 50 cents - and the packaging about the same - so about a dollar is the cost of the media. But even when amortized over millions and millions of copies - development costs in the hundreds of millions are not trivial! Think instead of the movie business. It costs hundreds of millions to make a movie - but the cost of shining a light through the film onto the screen pretty much pays for itself from the money you spend on a soda and a medium popcorn. Why aren't movies free? Same deal. SteveBaker (talk) 00:10, 24 March 2009 (UTC)
Yep, and in addition to the lower costs of developing for a nearly uniform platform (in practice it's not quite fixed, as modern consoles have varying firmware and very occasionally hardware revisions are material) that gives then a similarly simpler support burden. And the piracy rate for console games is much lower. Dog Day Today (talk) 17:14, 23 March 2009 (UTC)
For the same reasons as Nespresso capsules, ink cartridges etc. It's a business model made possible by complete vertical integration. I'm guessing that Sony et al. make relatively small margins on consoles, knowing that this will seduce users ("Consoles are so much cheaper than PCs", "The printer came free when I bought the computer", "It costs far less than a real espresso machine"). As they have complete control over the "ecosystem" (something that is not the case for PCs), they can make their profits by taking their cut on every game/capsule/cartridge you buy instead of having to make it all in one go. Console games are as "overpriced" as the consoles themselves are "underpriced". It's just a different way of making money (more adapted to kids, with their regular weekly income and aversion to saving). yandman 17:29, 23 March 2009 (UTC)
I think, in addition to the above, it's something to do with copy protection. PC game makers, although some of them still try, have mostly accepted that that is going to be a crack and pirate copy on the net. A PS3 game, on the other hand, is almost impossible to copy - therefore they can charge more, knowing people are forced to buy these games. PS3 games are so overpriced that rentals are becoming popular (where I live at least). Also, the average person that buys a "TV Game" (as they fondly call it) knows a lot less than the average PC enthusiast, and would have no idea how to copy an xbox or PS2 game anyway. This person would see no alternative but to buy games. The price of games is a shame, as I know kids who have to save for months to buy their favourite game. Sandman30s (talk) 19:59, 23 March 2009 (UTC)

The dirty truth is this. When you buy a PC, you pay what it costs to make - plus some profit for the manufacturer. When you buy an Xbox or a Playstation, you're buying approximately the same 'stuff' - but you're paying a LOT less for it. An Xbox essentially IS a PC - the original Xbox particularly.

In fact, consoles are so cheap that you're almost certainly paying less money than it costs to make the thing! Both Sony and Microsoft lose money every time someone buys one of their consoles! They make their money back (in theory, at least) by charging the game manufacturers (or their own game manufacturing groups) a certain amount of money for the privilage of making games - and a certain amount for every game they sell. Hence, so long as everyone who buys a console buys a statistically reasonable number of games, the console manufacturer makes a profit. However, in PC land, there are hundreds of manufacturers and anyone can write software for any of them. The manufacturers make their profits by selling their hardware at a profit. Hence there are zero licensing fees for game manufacturers - and generally, they pass those savings on to the consumer. There are some other issues at play - but that is far and away the largest. Of course there are exceptions - Nintendo makes a small, but significant, profit on the Wii console (despite being sold so cheaply - it has no hard drive, very much less memory and a smaller, cheaper CPU+Graphics system). However, Nintendo are still able to charge people for the privilage of making and selling Wii games - so they make profit both ways! There are other small savings for the PC game makers - one is that when you make a game for Sony/Microsoft/Nintendo, you have to pass fairly strict quality guidelines and they may also require that certain advertising rules are met. If you write for the PC, you can push out any old crap and get away with it.

One interesting side-effect of that is the perpetual shortage of new machines when they first come out. Remember those L-O-N-G lines to buy the new Xbox? You might ask yourself: If their big market is just before Xmas - why on earth don't they make enough machines for everyone? Well - here's the reason...because they lose money on every machine they sell - the more they sell over Xmas - the more money they lose! They can't make the money back from game sales because there aren't enough games on the market yet. The game's manufacturers don't want to put out a new game on a new console because there aren't enough of them out there yet to justify the development cost. So you have this giant "chicken and egg" situation. The console manufacturers only want to sell just enough machines to pursuade the game developers to make games for it...only when they've got some money back from game sales can they afford to put more machines out there. So as game revenue comes in - they can afford to lose more money by selling new machines to boost game sales and allow them to make more machines! The whole market isn't driven by making huge numbers of machines to turn a massive profit - it's about rationing machines so that only the most fanatical game players buy them...the ones who will buy the most games. The last thing they want (and one of the big problems with the PS-3 launch) is people buying the machines just to surf the web.

This pricing model is a bit odd - but it's becoming more commonplace - when you buy a printer, you're paying quite a bit less than it costs to make - and the manufacturer hopes to make money by charging through the nose for ink. We get cellphones for much less than cost - providing we sign up to use them for a couple of years on just one network. It's a rather nasty practice IMHO. I'd rather pay what things cost. The idea is that they make something look amazingly cheap - so you rush out and buy it - without a thought for how much it's going to cost you in ink/minutes/games over the life of the machine. But if you are that rare individual who buys a console and only one game - or a printer and prints so rarely that they never need another ink cartridge - then you're onto a good deal. The downside (IMHO) for the games business is that it effectively rewards the person who hardly ever buys a new game - at the price of ripping off your core demographic - the person who buys 20 or more games over the life of the console.

So - how long will it be before you can buy a car at half price if you can only run it on gasoline from one manufacturer at $10 per gallon? I think it would happen if they could figure out a way to stop you putting regular gas into it instead.

SteveBaker (talk) 23:49, 23 March 2009 (UTC)

I would point out the mobile thing is far less common in many countries in the Asia Pacific region where prepay is common and locked phones often unheard of. Nil Einne (talk) 10:50, 28 March 2009 (UTC)

Priority over wifi network[edit]

Hi, I regularly have to download large files over a wifi network for work. Every time I'm downloading, and even when I limit the rate, it blocks access to the internet for the computer that is plugged directly into the router. Is there any way to give it priority so that its internet access is not affected? Thank you (talk) 17:21, 23 March 2009 (UTC)

It shouldn't be able to block access completely...the ethernet just doesn't work like that. I wonder whether your router is limiting the number of simultaneous connections - or the number of DHCP addresses it hands out? SteveBaker (talk) 23:12, 23 March 2009 (UTC)
The feature you're looking for is called Quality of Service (QoS). Some consumer routers support basic QoS settings; others can be upgraded with third-party firmware (like dd-wrt) to add QoS. You can simply increase the "priority" of the second computer to prevent starvation. – 74  01:48, 24 March 2009 (UTC)
I'll have a good look into it, thank you very much. (talk) 02:46, 24 March 2009 (UTC)
This link from the article seems to say that the only place where QoS can be applied in an ethernet/wifi configuration is in the upload part. Anyone know how to give download priority to the ethernet connection? Thank you. (talk) 02:58, 24 March 2009 (UTC)
You can't control your ISP's routers, but if your router is prioritizing certain connections and dropping other low-priority packets then the low-priority connection will effectively be throttled. This is necessarily a reactive, not a proactive, strategy, mostly useless for low-latency applications (like internet telephony) but perhaps acceptable for your specific application. You might also read Bandwidth throttling; if you directly throttle your download speed on your first computer (by using a download manager, for instance) then the second computer should have no problem accessing the internet. – 74  03:55, 24 March 2009 (UTC)
Be sure and check out DD-WRT's supported devices before flashing it to your device. Some newer Linksys routers require a stripped-down "mini" version, due to memory constraints. They do still make a special version called the WRT54GL which works well for custom firmware, though. Spidern 13:11, 25 March 2009 (UTC)

WEP Key[edit]

Alright, can somebody please tell me (in simple English, please ;D) how to find my WEP Key? (talk) 17:36, 23 March 2009 (UTC)

If it's your WEP key, there's usually a sticker on the underside of your ADSL box. And if there isn't, just plug in an ethernet cable and access the config page. yandman 17:49, 23 March 2009 (UTC)
If it's not your WEP key look up Backtrack 3, it contains lots of tools for getting keys —Preceding unsigned comment added by (talk) 18:08, 23 March 2009 (UTC)
yandman is right that the default wep key is often pasted to the newer routers. However, if you want to make sure that it is still the actual key being used, or if you're looking at an older box - you can login to the router ( is common but not absolute). Depending on the brand and model, the config page you'll want to look at is the wireless settings, and perhaps a security sub-tab to find the current WEP encryption key. — Ched ~ (yes?)/© 21:09, 23 March 2009 (UTC)
With many wireless boxes (but not all) you can connect your computer up using an ethernet cable (it WON'T work via wireless) - and point your browser at - this is usually a tiny little 'mini-website' that's running from inside your router/wireless box (this somehow never ceases to amaze me!). If it demands a password to log into it - and if you don't know that password either then you'll have to do a 'master reset' on the box - which will probably set it back to factory defaults. Don't do that unless you are reasonably confident that you know enough about setting up such things. Anyway - you need to find the reset button on the box (it's usually in a little round hole underneath somewhere and needs to be pressed in with the tip of a ballpoint pen or something - and perhaps held in for 10 seconds or something). That should allow it to come up without a password - and probably resets the WEP password too. Either way - you can now get into the box - and you should find a whole bunch of menu options on the web page. One of these will let you set up the admin password (I strongly advise you to do that) - another lets you set the name of the router, the encryption scheme you want and the WEP passkey (assuming you decide to opt for WEP as your encryption scheme). Be sure to write these things down and put them somewhere secure so you can find them next time! (And sticking them on the underside of the box isn't really a security risk since anyone who can get at the underside of the box can reset it just like you just did). Running the box with the default encryption key is probably a bad idea anyway. SteveBaker (talk) 23:10, 23 March 2009 (UTC)
Just a quick note : The password might be a blank password. I mean that leaving the password box completely blank might actually work. Some routers default to that. (Possibly with "admin" as the log-in name.) APL (talk) 13:39, 24 March 2009 (UTC)
Am I misparsing you, or are you claiming it's impossible to log into a router via wireless? I can certainly log into my Netgear WGR614v9 router without a wired connection. Algebraist 23:04, 24 March 2009 (UTC)
There is no reason why it would be impossible, but it is disabled (or only optionally enabled) on some routers as a "security feature". Similarly, configuring the router from the WAN uplink is usually disabled. Considering many owners don't bother to change from the default password (if they even access the router at all), I'd have to say that it's a reasonable precaution. – 74  02:23, 25 March 2009 (UTC)
Well, you CAN enable 'wireless admin' but I strongly advise against it. It only takes for someone within radio range to do a successful dictionary attack against the password and you're doomed. SteveBaker (talk) 03:50, 25 March 2009 (UTC)
Right, because once they've cracked your ultra-secure router configuration they can… use your internet connection? Reconfigure your router to reject your connections, forcing a reset? Eavesdrop on "private" wireless communications? The thing is, to be able to access the configuration page they would have had to crack your wireless encryption key, which means they already have access to your internet, your private network, and your wireless communications. "Doomed" would seem to be a bit of an overstatement here. – 74  04:15, 25 March 2009 (UTC)
One thing they could do is change the default DNS server to one they control. That opens up various MITM attacks which they can conduct at their leisure from a remote location. -- BenRG (talk) 16:35, 25 March 2009 (UTC)
Fair enough, but that's going to a lot of trouble to capture the internet accounts of someone who uses dictionary passwords. Quite frankly, if someone is truly paranoid about their network security then they should disable wireless access entirely, not just wireless configuration. Meanwhile, everyone who doesn't believe the world is out to get them would be better served by using a strong router password than disabling wireless configuration. (It is, however, best to disable wireless configuration if you know you aren't going to use it.) – 74  23:45, 25 March 2009 (UTC)

Online services request email password[edit]

I signed up for Facebook, and am unhappy to see that the service repeatedly asks for my email password. Access to my email would grant access to any passwords emailed to me by other online services. The excuse that they want to search my email to see who I might wish to befriend seems pretty flaky. Has there been any discussion of this as a possible identity theft or password stealing ploy? I have never seen any reputable online service ask for my password for any other service. Edison (talk) 19:21, 23 March 2009 (UTC)

There is absolutely no reason for Facebook to require your email password. Either you are misunderstanding them or it isn't Facebook that is asking. It is probably a phishing scam. --Tango (talk) 19:23, 23 March 2009 (UTC)
Facebook does have a 'find friends' feature which works as you have described. I've never used it and (as far as I can recall) Facebook has never spontaneously suggested it to me. If Facebook keeps asking you to use this feature, then you should report this as a problem. Algebraist 19:25, 23 March 2009 (UTC)
It does? Well, there you go. I have always resisted signing up to Facebook (I must, by now, but the only student in the world that doesn't have a Facebook account) - I've never liked the idea. Sites that help you communicate with people you rarely see in real life are one thing, but most people use Facebook to communicate with people they see in lectures several times a day. The only useful feature is events invites, and my friends have long since got used to the fact that whenever they send out a Facebook invite they have to let me know separately (and they've long since given up complaining about it, too!). --Tango (talk) 19:34, 23 March 2009 (UTC)
It becomes more useful when you are out of school—it lets you find folks you went to school with but have since parted ways with. -- (talk) 20:21, 23 March 2009 (UTC)
Quite a few of them do it - Twitter's another. Google even provides an API for accessing contacts data. They're not demanding it, and you can sign up without providing it. Facebook also lets you upload contacts as a CSV file if you want to find your contacts but don't want to supply your email login details. (But yes, in general it's sensible not to use login details from one service on another. A password management program like KeePass may be a better idea than keeping passwords in your email inbox, though) — Matt Eason (Talk &#149; Contribs) 19:36, 23 March 2009 (UTC)
Google's approach is much better—the API allows you to grant access to your contacts data without giving access to your e-mail or your password. Whether you want a site trawling through your contacts is another question entirely than whether you should have to give them access to your entire e-mail account to do so. -- (talk) 20:20, 23 March 2009 (UTC)
It's really really really irritating that sites do this. Just say no. For those who don't know about this, here is a nice blog entry on the practice, which lots of sites now utilize. -- (talk) 20:18, 23 March 2009 (UTC)

It's silly to assume that I would want an online service to issue a "personal invitation" in my behalf to everyone I have ever emailed to join that service. Much better for an individual to issue invitations to those few individuals who might remotely be considered "friends." Edison (talk) 03:14, 24 March 2009 (UTC)

Agreed 100% but remember that their primary demographic are students who aren't using e-mail for, say, professional life. Obviously if one's e-mail is part of a formal professional network you don't want to invite everyone to be your "friend", but if you're in high school... -- (talk) 13:18, 24 March 2009 (UTC)
The occasionally interesting blog "Coding Horror" did a post on the topic a while back, here.
To me it feels like a dangerous practice. System administrators spend a lot of effort trying to educate users that it's never OK to give your password out, and that no one but yourself has a legitimate need for it. And then this comes along and confuses people. Worse, think of how many passwords must be stored, in cleartext, in the databases of these social networking sites!
It's a stupid solution to a problem, but people will accept it until it causes a disaster or two. APL (talk) 13:37, 24 March 2009 (UTC)
Be careful when anybody asks you for your password, especially by email. It's possible that it is a phishing scam which was brought on by a virus or malware that is running on your computer. Do a virus check (see AVG Antivirus) and a malware check (try Malwarebytes' Anti-Malware, they have a free version) to ensure that your system is clean. Spidern 13:06, 25 March 2009 (UTC)

DVD audio selection[edit]

My TV has a 2.1 speaker system (right speaker, left speaker, and subwoofer). Most DVDs have the choices for 2.0 or 5.1 audio. Which would be best for a 2.1 speaker system ? What happens if I choose 2.0, do I get nothing sent to the subwoofer ? What happens if I choose 5.1, do I get 3 of the speaker channels just dropped ? If so, which 3 ? StuRat (talk) 20:34, 23 March 2009 (UTC)

I believe that 2.1 audio only contains two channels (stereo); the subwoofer merely produces the low-frequency content of these channels, i.e. the tones the two normal speakers cannot produce. Thus, a 2.1 speaker system is designed to work with stereo (2-channel) audio, i.e. 2.0. If you choose 5.1, I guess (but I do not know) that the channels merge to stereo. --Andreas Rejbrand (talk) 20:44, 23 March 2009 (UTC)
Btw, have you read Surround sound? --Andreas Rejbrand (talk) 20:50, 23 March 2009 (UTC)
That just made things more confusing, since there are apparently 4 different types of 5.1 audio, and I have no idea which the DVDs use. StuRat (talk) 21:32, 23 March 2009 (UTC)
Yes, I see now that the article might not be the right one for you. Nevertheless, the answers to your questions, I believe, are
  1. The low-frequency content in the two stereo channels will be produced by the subwoofer. Probably your 2.1 speaker system is designed to work with 2-channel (stereo) audio sources, automatically sending the low-frequency content to the subwoofer.
Of course it would be possible to have three distinct channels for left, right and subwoofer, but I think this is very uncommon.
  1. If you try to play multichannel (e.g. 5.1) audio on your 2.1 speaker system, the most reasonable thing to happen is that the five audio channels merge to only two channels: your left and right channels. For instance the right stereo waveform will probably be a linear combination (perhaps with coefficients ~1/3, ~1/3, ~1/3) of the center and the two right channels in the 5.1 arrangement, and the corresponding is true about the left stereo waveform. Consequently, no audio information (no channel) is really "lost"; no channels are "dropped" or ignored. This is the reasonable way of playing 5.1 audio on a 2.1 system – how your system is implemented, I do not know, though. --Andreas Rejbrand (talk) 22:35, 23 March 2009 (UTC)
Thanks, it sounds like the 2.0 is the best choice, then. StuRat (talk) 23:33, 23 March 2009 (UTC)
I'm not sure all the advice here is 100% accurate. I always thought 5.1 meant six discrete channels, and each channel is encoded separately on a DVD using 5.1 AC3 encoding. Look at the article Dolby Digital - this says that if you choose 5.1 on your DVD player, it should use downmixing (or downsampling) to transfer the relevant channels to your 2.1 system. Therefore, 2.0 is not the best choice for a DVD as you will miss out the LFE (subwoofer) sound from the ".1" channel. Sure, if you played an audio cd and chose surround sound, you would get upmixing or upsampling to get the full range of sound on all your speakers. So, I think 5.1 is the best choice as most DVD players support downmixing. Sandman30s (talk) 22:01, 24 March 2009 (UTC)
I do not see where I have been mistaken. --Andreas Rejbrand (talk) 23:00, 24 March 2009 (UTC)
...although I did not mention (or even think about) the fact that the possible LFE channel in 5.1 may be used in the downsampling to 2.1, to give a slightly different (and, hopefully, more appropriate) subwoofer signal than what would be the result of automatic extraction from a pure stereo signal. --Andreas Rejbrand (talk) 23:06, 24 March 2009 (UTC)
OK, then I'm back to picking 5.1. I wish they had a test sample (with subwoofer and all other channels played sequentially), so I could easily determine which is best. StuRat (talk) 14:44, 25 March 2009 (UTC)
Computer soundcards normally come with a utility that tests each channel. This would mean connecting your computer to the audio-in of your DVD player (or amp) though - not sure how comfy you are with that. Sandman30s (talk) 12:06, 26 March 2009 (UTC)

Assembler syntax[edit]

I have a ARM/Linux hello world:

.global _start
mov r0, #0
@ no '#' next line?
adr r1, msg
mov r2, #msglen
mov r7, #4
swi #0
mov r0, #0
mov r7, #1
swi #0

.ascii "hello arm\n"
msglen = . - msg

Why is there no '#' in front of msg on the "adr r1, msg" line? I think it has something to do with the label being "derefenced", but I can't find any instruction that wouldn't cause a syntax error both with and without a #, not that I had tried very hard. So, a) is something similar common in other architectures and b) is there some general rule for when a # should be used? I'm using gnu assembler. -- (talk) 21:10, 23 March 2009 (UTC)

If in doubt - write the same thing in C and compile it with the '-S' flag ("Stop after compilation - do not assemble") - and look for a '.s' file containing assembler source. SteveBaker (talk) 22:53, 23 March 2009 (UTC)
In ARM assembly language, the # denotes an immediate operand, i.e., a fixed value that is actually stored with the encoded instruction. The numbers 0, 1, 4, and even msglen (which the assembler will calculate to be 10) are fixed values that can be stored with the instruction. In contrast, msg refers to a location in memory which is not fixed at the time the program is assembled. Each time the program is run, it might be loaded into a different location in memory, so the address of msg would change. -- Tcncv (talk) 01:12, 24 March 2009 (UTC)
adr is a pseudo-instruction or macro. It can map to a variety of instructions and possibly an out of line literal but always means get the address of the operand into the register. The mov instruction on the other hand has a variety of different possible operands, # would mean the operand is a literal rather than a register. so 'mov 1,2' means load the contents of register 2 into register 1 whereas 'mov 1,#2' means load the literal value 2 into register 1. Dmcq (talk) 08:38, 25 March 2009 (UTC)


If I have a list of words in English, is there a way I can translate them in one go. I have them on excel and in html format. The language I wish to use is Polish but even as a general enquiry about other languages. (talk) 21:24, 23 March 2009 (UTC)

Have you noticed Google Translate? It might not translate all of them with one go if there are many. -- (talk) 21:43, 23 March 2009 (UTC)
Just a general note: you probably shouldn't rely on machine translation for anything important. Its reliability is kind of iffy at best, and can have misleading or embarrassing results. -- Captain Disdain (talk) 22:50, 23 March 2009 (UTC)
But the advantage a human translator has is in being able to use the context to provide a custom translation. When you are just given a list of words, there is no context, so a human translation may be just as bad as a machine translation, in this case. StuRat (talk) 23:30, 23 March 2009 (UTC)
Well, I've done a lot of translation work (some of which has included cleaning up confusing messes made by machine translation), and the problem here is that there tends to be a lot more ambiguity between words than people think. You're right in that context is everything, but unless the list is a list of truly random words, there's probably more context there than you might think. If you've got a list of video game-related words, to pick a random example, and one of the words is "controller", that's context right there, but what the automatic translation spits out probably won't be the correct Polish translation for that, but another translation for the word. Also, when you have a list of words, in my experience a lot of the time that won't be a list of single words. It may include things like, oh, "action game" or "power-up" or things in that vein, which is likely to confuse the translator program even further, and it'll spit out one word for "action" and another for "game", but the end result may not be even remotely comprehensible. A practical example: "game", in English, refers to both a game (as in video game) and something kids do outside, but in Finnish the word is not interchangeable -- the former is "peli" and the latter is "leikki". For all I know, Polish has a similar situation. I'm not saying that you can't produce something reasonably understandable with machine translation, but you shouldn't rely on it to be accurate, and to a native speaker, it's probably going to be painfully obvious that you don't know what you're doing. If that's not a concern for some reason, then what the hell, it's a quick and easy fix, but no one should rely on it in a professional or academic context unless you're prepared to take the credibility hit. I guess the underlying moral here is that if you don't know the language and still translate it without any input from someone who does, the end result is likely to be bad. -- Captain Disdain (talk) 09:08, 24 March 2009 (UTC)
I'm Polish and a translator. I could have a look at your list if you want. Is the word list long? --Ouro (blah blah) 08:20, 25 March 2009 (UTC)

Thanks for th offer but the list is very long. I was hoping to translate it all in one go. As for context, my girlfriend is Polish and is currently studying for exams but she will be able to check my translations anyway, manual or computerised. I thought a quick method would be better. I guess its not possible but I'm getting through it. Thanks (talk) 10:31, 25 March 2009 (UTC)

Directory after remaming a user[edit]

I renamed my account (Kevin Duke -> Kevin) but none of the directories are changing. How can I fix this? (screen shot to right) -- penubag  (talk) 22:34, 23 March 2009 (UTC)

I'm afraid there's not really a perfect solution here as the directory/registry entries are only created at the point the user account is first logged on and it's never updated. Basically it involves renaming the account back, creating a new profile of Kevin, logging it on once (to create the correct directory) and then copying the Kevin Duke profile on top (using the Control Panel|System|User Profiles function to do this, not just copying the files in Explorer). Technically you could do a lot of registry editing (both both current user and local computer so the location changes and the directories still work) and just rename the directory on the disk but I've personally never tried that and it might make things really bad. Either way it's very messy and I'd totally advise against it as not all settings will migrate correctly and could cause you serious login problems if it goes wrong. To make it even more complicated you'll need a 3rd account to do the copying as you can't copy to/from a profile if you're logged into either account and likewise you'll need to reboot first to completely "unlock" an account to allow you to copy it. I know you renamed your account because of your earlier problem on here, but I would recommend simply renaming the user account back and creating the Kevin account (with the same password as on your other machine) and simply not using it as a login account (this was actually what I posted in the thread). You only needed to create the account so it would exist/authenticate again, you don't actually need to log in with in on the machine itself although with hindsight if you have the XP friendly logon screen showing you probably don't want the other account showing, but there is a way round that/hide accounts if needed. Sorry for any confusion caused. ZX81 talk 16:51, 24 March 2009 (UTC)
Thank you, I will try this tomorrow. -- penubag  (talk) 05:17, 26 March 2009 (UTC)
I believe MS's TweakUI can do this in XP (Change system / My Document folders), but have not tried in vista yet, but its worth a shot. PrinzPH (talk) 17:39, 24 March 2009 (UTC)